Improvement in piano-forte feames



@glut-ith tatrsstent @.fm,

ANDREW FERDINAND DESSAU, OF WASHlNGTON, DISTRICT OF COLUMBIA.

Lut-ters .Patent No. 75,132, dated llfarct 3, 1868.

IMPROVEMENT IN PIANO-FORTE FRAMES.

itin .Stiftbxzlt ttfrtnh tu in llgese grltrrs lmnu mit making part uf the stmt. Q-

To ALI. wuozu 1T MAY C0NeEnN Be it known that lI, Annnnw Fnsmnann Dessau, of the city of Washington, in the District of Columbia, have indented a new and useful Improvement in Piano-Fortes; and I do hereby declare the following to be a full and correct leseription'ot',`tlie same, sutiieient to enable others skilled inthelurt to which my invention appertains to fully understand and use the same, reference being had tc the accompanying drawings, which make part of this s'pecilcation, 'and in whieh-- Figure A1 is u perspective view of the frame ota piano, showing my improvements.

Figure 2 is a' cross-section of iig. 4 in line a: 2:.

Figure 3 is a longitudinal section ofthe same in line yy; und

Figure 4 is n bottom view of the frame.

Like letters indicate like parte in the several figures.

The nature of my invention consists in constructing the bottom et' a square piano with openings atits bot` tom, so that the tone may swell out from under the sounding-board, asl in grand pianos, in which there is no framework under the sounding-board.v Also, iu a peculiar construction of and wey tif-attaching to the frame the bars of the bottom oi the piano, and their position in relation to the strings, so theros no obstruction offered to the tones as they swell out, nor can the strain ofthe strings warp the bars or beams.

'lhe great superiority of grand pinnos over square ones is their greater power oftone, which is obtained by their'peenliar"construction, allowing the bottom to be open, and the sound toeeme out free and unobstructed from the sounding-board. In square pianos, 'this is not possible to attain, as -the frame would be warped and bent by the power of the tension of the strings, which, in common six-octave pianos, amounts to about thirty thousand pounds, were the bottom left olf; said bottom having to be made in one piece, for if it were constructed of beams,.c onnoeted in the usual manner of connecting piano-frames,= that is t'o say, glued, they would not be able to withstand thepower ofthe tension of the strings; and the effects of heat and cold, in fact all changes of the weather, would soon so warp the beams and frame of the piano ns to 'keep it continually out of tone, and wthonta remedy.` I- overeomo this difficulty, and am enabled to construct a common square piano with an open bottom, by means ofconstructing the cross-bars or beams and the frame of a piano of layers of pieces of wood; the grain of them-ood running in opposite directions in contiguous pieces, as shown in'g. 2, interlocking these layers of pieces where the beams are joined to the frame, or among each other, sous to'form u. kind of straight dove-tailed joint. A Y

A, in the drawings, may represent thc frame of a square piano, the bottom of which is formed of parallel pieces, B D* and B B", and C; tho latter being a oross-piece placed at about the place where the treble-strings are fastened. -Between the beams D and C are cross-pieces D and E, all constructed, as described, of layers, and attachcdto beams B2 and C, and to each other, by overlap-ping the dillerentlayers, as shown in'iigs. 1 and 3'; alternate layers of the same pieces running parallel and atright unulc's with the alternate layers ofthe beam to which they are attached. In this manner the grain of no two layers runs parallel, and each beam is constructed of such layers glued to each other. Between the beams C and the side nro-the ctoss-pieces F, cons tructed and secured in the same manner as the pieces D and E, 'which 'lie under that part of -the iron frame G over and on wbich the overstrung base-strings are secured. i. i

' It will be seen that the beams D run .parallel with tho brise, and the beams E parallel with the trcblestrings of the piano, so that there is no piece situated across thel wnyc of sound, and the 'latter isfroo to swell out from under the sound-board without obstrdCtiOn.

Bythis improvement Iam enabled to produce a square piano equal in volume and power of sound to any grand piano, and combining with this superior strength. l

Having thus described my inrention, what I claim as new, und desire to secure by Letter"l Patent, is-

' 1; Constructing the bottom 'beams andframe of a piano of layers of pieces of wood, in the manner substantiully as and for the purposes described.

2. Constructing-the beams and frames otl pianos by building the sume up in the manner substantially as described. I

ANDREW FERDINAND DESSAU.

Witnesses:

Jncon HENRY, Anexa. A. O. Ktnvcxn. 

